An otherwise healthy 39-year-old man with a dark spot in the visual field of his left eye showed retinal whitening, indicating a cilioretinal arterial obstruction and minor signs of venous stasis at the initial examination. The affected cilioretinal artery filled normally during fluorescein angiography. The visual acuity was 1.0 bilaterally. One week later, the retinal whitening had decreased and signs of central retinal venous occlusion (venous dilatation, retinal haemorrhages and papillary oedema) predominated in the fundus picture. The patient was treated with oral betamethasone and acetylsalicylic acid. The patient was free of symptoms and the fundus normalized within 10 months. The pathogenesis of cilioretinal arterial obstruction combined with central retinal venous occlusion is not established. The clinical course in this case seems to favour a hypothesis of a primary arterial affection.